A radio-frequency device connector (radio-frequency connector) for communication equipment is an electromechanical component for connecting a conductor (wire) with an appropriate matched device so as to realize connection and disconnection of microwave signals. As an indispensable component in a passive device, there can be varied forms and structures of the radio-frequency connector, and various radio-frequency connectors in different forms can be chosen according to different application objects, frequencies, powers, application environments and the like.
In mobile communication engineering, two types of radio-frequency connectors, namely an N type radio-frequency connector and a Din type radio-frequency connector, are frequently used, wherein the N type radio-frequency connector is suitable for being used as a medium power or low power coaxial cable connector with a threaded connection mechanism. Compared with the N type radio-frequency connector, the Din type radio-frequency connector is capable of bearing a higher input power, and thus is generally used in high-power application occasions, for instance, a radio-frequency output port of a “macro” base station. The Din type radio-frequency connector usually includes two parts, namely, a plug (male) connecting piece and a socket (female) connecting piece.
A small-Din type radio-frequency connector, also called a Mini-Din type connector, is a frequently used Din type radio-frequency connector. According to different sizes of connecting interfaces, the small-Din type radio-frequency connectors also can be divided into 4.1/9.5 type and 4.3/10.0 type radio-frequency connectors.
The 4.1/9.5 type radio-frequency connector, which had been established as the standard (IEC60169-11) by the International Electrotechnical Commission (IEC) in 1977, is a radio-frequency connector first developed and practically applied to a communication system, and is mainly used in base station antennas.
In a mobile communication system, passive intermodulation (PIM) is gradually becoming a major reason of interference. PIM is produced when powers of radio-frequency signal with two or more frequencies simultaneously appear in a passive device; such PIM is a mixed signal produced due to a nonlinear characteristic of connection of heterogeneous materials, wherein one representative mixed signal is called a third-order intermodulation signal. PIM may interfere with a receiver, and may enable the receiver to be unable to work normally in a severe case; hence, it is crucial to suppress intermodulation interference.
With the development of the mobile communication technology, PIM performance must pass increasingly high requirements. In 2014, the major global radio-frequency connector manufacturers derived and developed a new small-Din type connector on the basis of the existing 4.1/9.5 type connector; the new small-Din type connector is named as the 4.3/10.0 type connector and also applied to antennas.
Hence, during the upgrading of the existing antennas, the two small-Din type connectors of different interfaces certainly may coexist for a while. In a practical mounting process, as the two interfaces are substantially similar in shape, and particularly the plug (male) connecting pieces substantially have no difference in their shapes, mounting personnel is apt to confuse the connectors of the two ports and carry out wrong mounting due to inaccurate distinguishment: namely, the mounting personnel may assemble the 4.1/9.5 type plug (male) connecting piece to the 4.3/10.0 type socket (female) connecting piece to cause damage to the port of the 4.3/10.0 type socket (female) connecting piece, thereby leading to scrapping of an antenna.